When are colds contagious?

Dear Healthy And Wanting To Stay That Way, 

The common cold is, as it’s called, very common! But there are things that can be done to prevent its spread to others. While there’s no hard-and-fast rule for when someone with a cold is contagious, there are still solid guidelines to follow like covering your nose and mouth when sneezing and washing your hand often. Read on to learn more! 

What is the common cold? 

Colds are a viral infection of the nose and other regions of the upper respiratory tract, like your sinuses and throat. It’s highly contagious, but generally mild and isn’t usually harmful to an otherwise healthy person. Colds are most common in the winter—reduced humidity and spending more time inside with other people may increase the likelihood that you catch one. 

Common cold symptoms can include:  

• Runny nose 
• Sneezing 
• Headaches 
• Lethargy 
• Sore throat 
• Cough

List adapted from Close Encounters of the Microbial Kind  

When are you contagious with a cold? 

You’re most contagious with a cold during the incubation period. This is the time between first getting the virus and when you start showing symptoms. For a cold, this period can be about two or three days or up to a week.  

Symptoms tend to peak one to three days after you start feeling sick and can last for about ten days. Colds tend to get better on their own, but mild symptoms may persist for a few weeks even after you’re no longer contagious.  

There’s no exact line between being contagious and not. A good rule is to wait until symptoms improve and you’ve been fever-free for 24 hours before getting back to your usual activities.  

What can be done to protect yourself and others from catching a cold? 

You can use a number of strategies to prevent spreading illness or getting sick yourself including:  

• Avoiding contact with people who are sick 
• Covering your mouth and nose when coughing or sneezing 
• Disposing of used tissues in the garbage 
• Disinfecting personal items and shared surfaces 
• Washing your hands before you eat or touch your face 

It’s also important to try to stay home or isolate yourself from others while your symptoms are at their peak. If you do need to be near other people, you might consider wearing a mask to protect those around you.   

How can you treat cold symptoms? 

There are many over-the-counter (OTC) medications available at pharmacies or drug stores that provide relief for cold symptoms. In addition, it’s recommended you get plenty of rest and drink lots of fluids as symptoms run their course. This will help your body replenish lost electrolytes and nutrients to maintain strength during illness and help your body recover more quickly. 

Check out the Common Cold Fact Sheet for more advice on treating cold symptoms and general common cold information!  

Is it normal to have symptoms linger after having a cold? 

It can be common to have symptoms, like a cough, linger after you start feeling better. These coughs (often called post-infectious coughs) can hang around for three to eight weeks after an infection. They’re often due to mucus draining from your nose to your throat causing irritation, or remaining irritation from the initial infection of your airways.  

To soothe these symptoms, consider trying: 

• Humidifiers to provide extra moisture to your nose and throat and to help keep your nose clear 
• Throat lozenges, cough drops, and honey to stimulate saliva production to soothe your throat 
• Menthol topical application or eucalyptus oil to reduce mucus production and clear your nose  
• Decongestants and nasal sprays to help reduce nasal drip or congestion  
• OTC cough syrups as a cough suppressant, especially at night so your sleep isn't disrupted  
• Use a saline rinse to clear mucus and allergens from the nose and throat  
• Gargle with salt water to soothe an irritated throat 
• Apply a warm, wet washcloth to the face to simulate a humidifier, and heat can soothe pain and pressure for a sinus headache

List adapted from Medical News Today

When should you contact a health care provider? 

Consider contacting a health care provider if you continue to develop symptoms or the severity of your symptoms continues to increase after about 10 days.  

Contact a health care provider if you’re experiencing: 

• Increase in the frequency or strength of your cough 
• Increase in the texture/thickness of the fluid your cough produces 
• Coughing up blood 
• Ongoing systemic symptoms like fever, body aches, chills, difficulty swallowing, changes in appetite

List adapted from UCLA Health 

If you have a history of serious conditions like asthma, lung cancer, congestive heart failure, or gastroesophageal reflux disease, catching a cold may be more life threatening. If you use medications like angiotensin-converting enzyme (ACE) inhibitors or are a smoker, lingering symptoms might signal something more concerning, in which case contact a health care provider. 

Hope this helps in keeping the common cold at bay!